I think it's possible - red flags (for example blog spam or commercial sites) seem easy enough to catch for a human; probably in an automatic way too, at least

I think it's possible - red flags (for example blog spam or commercial sites) seem easy enough to catch for a human; probably in an automatic way too, at least as long as you're small enough that they don't specifically target you. Google's search results are so bad I can't really alledge incompetence here but have to wonder whether there's some different motivation. Maybe it's that low quality search results tend to be plastered with ads, which they get a cut on.